Rotary cutter.



A. s. vosn. I ROTARY CUTTER.

APPLICATION FILED MAY 6, 1911.

1 ,019,728. Patented Mar.5, 1912.

WITNESSES: INVENTOR. W 2X76? ATTORNEY.

UNITED STATES Ee TENT OFFICE.

AMBROSE S. VOSE, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF T0 ARTHUR F. GRAY, OF WATERTOWN, MASSACHUSETTS.

ROTARY CUTTER.

Specification of Letters Patent.

Application filed May 6, 1911.

Patented Mar. 5, 1912.

Serial No. 625,642.

T 0 all whom it may concern:

Be it known that I, AMBnosn S. Vosn, a citizen of the United States, residing in Brookline, county of Norfolk, and State of Massachusetts, have invented an Improvement in Rotary Cutters, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention relates to rotary cutters of that class employed in the manufacture of boots and shoes and is herein shown as embodied in a rotary cutter for trimming the edges of the soles of boots and shoes.

The present invention has for its object to provide rotary cutters of the class described with knives or blades of novel construction as will be described, which offer a su'tliciently reduced surface for contact with the edge of the grinding wheel, commonly employed for grinding the knives, so as to prevent said edge being rounded over, whereby the front face of each knife is maintained parallel with the back face after each successive grinding, and which accomplishes this result without weakening the knife to such extent as to render it liable to be broken in service or to be sprung or cracked in the process of tempering the same.

Each knife may and preferably will be provided on one side with a recess for the reception of the head of a clamp screw, so that the latter may be flush or substantially flush with the side of the cutter head, for a purpose as will be described.

These and other features of this invention will be pointed out in the claims at the end of this specification.

Figure 1 is an elevation of one form of rotary cutter provided with cutting blades or knives embodying this invention. Fig. 2, an enlarged view of one form of the knives shown in Fig. 1. Fig. 3, a view like Fig. 2 showing the condition of the knife after it has been ground. Fig. 4, a side View of the knife with the grinder wheel shown in dotted lines. Fig. 5,a front view of the knife and grinder shown in Fig. 4, and Fig. 6, a side view of a knife and grinder to illustrate the advantages of the present invention.

Referring to the drawing, or represents the head of a rotary cutter, such as is used on machines for trimming the edges of the soles and heels of boots and shoes, said head having secured to it a plurality of cutters or knives b.

The cutter or knife I), in the present instance, is shown as provided with a cutting edge 0 of the proper form or shape for trimming the edge of the sole of a boot or shoe, said cutting edge extending from the front face (Z to the back face 0 of the knife at an angle, after the manner of cutters or knives of this class, which are employed on shoe trimming machines.

In accordance with the present invention, the cutter or knife is provided on its front face (Z below the cutting edge 0 with a plurality of holes 10, herein shown as three in number, and arranged in a row, which extends transversely of the knife. The holes 10 may be formed by drilling into the front face of the knife, for preferably substantially one-half the thickness of the knife, and are separated from each other by narrow intermediate walls 12, and are located between the opposite sides of the knife so as to leave the front face of the knife unbroken or continuous at its opposite sides, whereby the said knife is not weakened to such extent as to render it liable to be broken off in use or to be cracked or sprung when tempered. Furthermore the holes 10 reduce the amount of metal in the front face of the knife to such an amount as to avoid rounding or turning over the edge 15 of the grinding wheel 16, which is commonly employed to sharpen the knife when its cutting edge becomes dull.

In knives of the character herein shown, it is essential that when ground, the parallelism of the front and back faces (Z 6, should be preserved, and to do this, it is necessary that the edge 15 of the grinding wheel, which makes contact with the front face of the knife, should contact with as little of the front face as possible. If the front face of the knife is left unbroken, the effect upon the circumferential edge 15 of the grinding wheel is to turn or round it over after the manner shown in Fig. 6, and as a result, the knife is not properly ground, as the parallelism of the front and back faces is destroyed. Prior to this invention, efforts were made to overcome this objectionable feature by providing the front face of the knife with a continuous slot extended transversely of the knife from side to side, but

this construction is objectionable as the formation of the slot removed so much of the knife as to render it weak and liable to break off in service and to spring or crack in the tempering process.

y with the holes 10, the desired amount of metal is removed from the front face to reduce the contacting area of the same to such extent as to avoid turning or rounding over of the circumferential edge of the grinder, without impairing the strength of the knife to such extent as to render it too weak for service or so as to be liable to crack or spring in the tempering process.

In Fig. 2, a knife is shown before it has been ground, and in Fig. 3, the same knife is shown after it has been ground. By ref erence to Fig. 3, it will be seen that in the ground knife, the parallelism of the front and back faces is preserved.

In Figs. 4 and 5, the relation of the grinder to the knife is represented, and by reference to Fig. 5, it will be observed that the circumferential edge of the grinding wheel 16 makes contact with a very small area of the front face.

The knives Z) are inserted into slots 17 in i the periphery of the cutter head a and are adjustable therein to compensate for wear, and to permit this adjustment and enable each knife to be firmly secured in its adjusted position by a screw 20, so that the head of the latter may be flush or substantially flush with the side of the cutter head, each cutter is provided in one side, which may be termed its outer side, with a curved recess 21, which extends to the front face [Z and whose bottom wall 22 is engaged by the head of the screw 20 when the knife is secured in fixed relation to the rotary head. The recess 21 is made of a curvature whose radius is greater than that of the head of the screw,

providing the front face of the knife which permits the knife to be moved longitudinally in its slot to adjust the same when worn.

I have herein shown the invention as embodied in a knife whose cutting edge is shaped to trim the edge of a shoe sole, but it is not desired to limit the invention to this particular kind of a knife, as the edge of the same may be of other shapes according to the particular work to be performed.

Claims.

1. A knife .of the character described, comprising a metal blade provided with substantially parallel front and back faces and a backwardly inclined outer face extending from the front toward the back face and forming a cutting edge with said front face, the latter having in it below the cutting edge a plurality of holes arranged in close proximity to one another in a row extended transversely of the blade, and a recess at one side of the blade and extended to the front face thereof below the said holes, substantially as described.

2. A knife of the character described, comprising a metal blade provided with'substantially parallel front and back faces and a backwardly inclined outer face extending from the front toward the back face and forming a cutting edge with said front face, the latter having in it below the cutting edge a plurality of holes arranged in close proximity to one another in a row extended 1 transversely of the blade, substantially as described In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

AMBROSE s. vosE.

Witnesses:

JAs. H. CHURCHILL, J. MURPHY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

